Synthesis and Electrochemical Properties of Nanocrystalline LiFePO<sub>4</sub> Obtained by Different Methods

Son, C.G.; Chang, D.R.; Kim, H.S.; Lee, Y.S.

doi:2011.2.2.103

J. Electrochem. Sci. Technol > Volume 2(2); 2011 > Article

Article

Journal of Electrochemical Science and Technology 2011;2(2):103-109.
DOI: https://doi.org/10.5229/JECST.2011.2.2.103

Synthesis and Electrochemical Properties of Nanocrystalline LiFePO₄ Obtained by Different Methods

C.G. Son, D.R. Chang, H.S. Kim, Y.S. Lee

Faculty of Applied Chemical Engineering, Chonnam National University;Korea Institute of Industrial Technology;Korea Institute of Industrial Technology;Faculty of Applied Chemical Engineering, Chonnam National University;

Abstract

Nanocrystalline $LiFePO_4$ powders were prepared at 660-$670^{circ}C$ in an Ar atmosphere using two different synthetic routes, solid-state and sol-gel. Both materials showed well-developed XRD patterns without any impurity peaks. Particles composed in the range of 200-300 nm from the solid-state method, and 50-100 nm from the sol-gel method, were confirmed through scanning electron microscopy and dynamic light scattering. The $LiFePO_4$ obtained by the sol-gel method offered a high discharge capacity (153 mAh/g) and stable discharge behavior, even at elevated temperatures (50 and $60^{circ}C$), whereas poor electrochemical performance was observed from the solid-state method. Rate capability studies for sol gel-derived $LiFePO_4$ ranged from 0.2 to 30 C, which revealed excellent retention over 70 cycles with a 99.9% capacity.

Key Words: $LiFePO_4$, Solid-state method, Sol-gel method, Cathode material, Lithium secondary battery